Chapter 4101:2-12 Hydronic piping

[Comment: When a reference is
made within this rule to a federal statutory provision, an industry consensus
standard, or any other technical publication, the specific date and title of
the publication as well as the name and address of the promulgating agency are
listed in rule
4101:2-15-01 of the
Administrative Code. The application of the referenced standards shall be
limited and as prescribed in section 102.5 of rule
4101:1-1-01 of the
Administrative Code.]

SECTION 1201

GENERAL

1201.1 Scope. The provisions of this chapter shall govern the
construction, installation, alteration and repair of hydronic piping systems.
This chapter shall apply to hydronic piping systems that are part of heating,
ventilation and air-conditioning systems. Such piping systems shall include
steam, hot water, chilled water, steam condensate and ground source heat pump
loop systems. Potable cold and hot water distribution systems shall be
installed in accordance with the plumbing code.

1201.2 Sizing. Piping and piping system components for hydronic systems
shall be sized for the demand of the system.

1201.3 Standards.
As an alternative to the provisions of
Sections 1202 and 1203, piping shall be designed, installed, inspected and
tested in accordance with ASME B 31.9.

1202.5 Pipe fittings.
Hydronic pipe fittings shall be approved
for installation with the piping materials to be installed, and shall conform
to the respective pipe standards or to the standards listed in Table
1202.5.

1202.6 Valves. Valves shall be constructed of materials that are compatible
with the type of piping material and fluids in the system. Valves shall be
rated for the temperatures and pressures of the systems in which the valves are
installed.

1202.7 Flexible connectors,
expansion and vibration compensators. Flexible connectors, expansion and vibration control devices
and fittings shall be of an approved type.

SECTION 1203

JOINTS AND
CONNECTIONS

1203.1 Approval.
Joints and connections shall be of an
approved type. Joints and connections shall be tight for the pressure of the
hydronic system.

1203.1.1 Joints between different
piping materials. Joints between different
piping materials shall be made with approved adapter fittings. Joints between
different metallic piping materials shall be made with approved dielectric
fittings or brass converter fittings.

1203.2 Preparation of pipe ends.
Pipe shall be cut square, reamed and
chamfered, and shall be free of burrs and obstructions. Pipe ends shall have
full-bore openings and shall not be undercut.

1203.3 Joint preparation and
installation. When required by Sections
1203.4 through 1203.14, the preparation and installation of brazed, mechanical,
soldered, solvent-cemented, threaded and welded joints shall comply with
Sections 1203.3.1 through 1203.3.7.

1203.3.1 Brazed joints.
Joint surfaces shall be cleaned. An
approved flux shall be applied where required. The joint shall be brazed with a
filler metal conforming to AWS A 5.8.

1203.3.4 Solvent-cemented joints.
Joint surfaces shall be clean and free of
moisture. An approved primer shall be applied to CPVC and PVC pipe-joint
surfaces. Joints shall be made while the cement is wet. Solvent cement
conforming to the following standards shall be applied to all joint
surfaces:

1. ASTM D 2235 for ABS joints.

2. ASTM F 493 for CPVC joints.

3. ASTM D 2564 for PVC joints.

CPVC joints shall be made in accordance
with ASTM D 2846.

1203.3.5 Threaded joints.
Threads shall conform to ASME B 1.20.1.
Schedule 80 or heavier plastic pipe shall be threaded with dies specifically
designed for plastic pipe. Thread lubricant, pipe-joint compound or tape shall
be applied on the male threads only and shall be approved for application on
the piping material.

Grooved and shouldered mechanical
joints shall conform to the requirements of ASTM F 1476 and shall be installed
in accordance with the manufacturer's installation instructions.

1203.3.8 Mechanically formed tee
fittings. Mechanically extracted outlets shall have a height not less
than three times the thickness of the branch tube wall.

1203.3. 8.1 Full flow assurance.
Branch tubes shall not restrict the flow
in the run tube. A dimple/depth stop shall be formed in the branch tube to
ensure that penetration into the outlet is of the correct depth. For inspection
purposes, a second dimple shall be placed 1/4 inch ( 6.4 mm) above the first
dimple. Dimples shall be aligned with the tube run.

1203.10.1 Heat-fusion joints.
Joints shall be of the socket-fusion or
butt-fusion type. Joint surfaces shall be clean and free of moisture. Joint
surfaces shall be heated to melt temperatures and joined. The joint shall be
undisturbed until cool. Joints shall be made in accordance with ASTM D
3309.

1203.13 Steel
pipe. Joints between steel pipe or
fittings shall be mechanical joints that are made with an approved elastomeric
seal, or shall be threaded or welded joints conforming to Section 1203.3.

1203.15.1 Heat-fusion joints.
Joints shall be of the socket-fusion,
saddle-fusion or butt-fusion type, joined in accordance with ASTM D 2657. Joint
surfaces shall be clean and free of moisture. Joint surfaces shall be heated to
melt temperatures and joined. The joint shall be undisturbed until cool.
Fittings shall be manufactured in accordance with ASTM D 2683 or ASTM D
3261.

1203.15.2 Electrofusion
joints. Joints shall be of the
electrofusion type. Joint surfaces shall be clean and free of moisture, and
scoured to expose virgin resin. Joint surfaces shall be heated to melt
temperatures for the period of time specified by the manufacturer. The joint
shall be undisturbed until cool. Fittings shall be manufactured in accordance
with ASTM F 1055.

1203.15.3 Stab-type insert
fittings. Joint surfaces shall be clean
and free of moisture. Pipe ends shall be chamfered and inserted into the
fittings to full depth. Fittings shall be manufactured in accordance with ASTM
F 1924.

1203.19.1 Compression-type
fittings. Where compression-type fittings
include inserts and ferrules or O-rings, the fittings shall be installed
without omitting the inserts and ferrules or O-rings.

1203.19.2 PEX-AL-PEX-to-metal
connections. Solder joints in a metal pipe
shall not occur within 18 inches (457 mm) of a transition from such metal pipe
to PEX-AL-PEX pipe.

SECTION 1204

PIPE INSULATION

1204.1 Insulation
characteristics. Pipe insulation installed
in buildings shall conform to the requirements of the applicable energy
conservation standard reference in chapter 13 of the building code;
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen
preparation and mounting procedures of ASTM E 2231; and shall have a maximum
flame spread index of 25 and a smoke-developed index not exceeding 450.
Insulation installed in an air plenum shall comply with Section 602.2.1.

1204.2 Required thickness.
Hydronic piping shall be insulated to the
thickness required by the applicable energy conservation standard
reference in chapter 13 of the building code.

SECTION 1205

VALVES

1205.1 Where required.
Shutoff valves shall be installed in
hydronic piping systems in the locations indicated in Sections 1205.1.1 through
1205.1.6.

1205.1.1 Heat exchangers.
Shutoff valves shall be installed on the
supply and return side of a heat exchanger.

Exception: Shutoff valves shall not be required when heat exchangers
are integral with a boiler; or are a component of a manufacturer's boiler and
heat exchanger packaged unit and are capable of being isolated from the
hydronic system by the supply and return valves required by Section
1005.1.

1205.1.2 Central systems.
Shutoff valves shall be installed on the
building supply and return of a central utility system.

1205.1.3 Pressure vessels.
Shutoff valves shall be installed on the
connection to any pressure vessel.

1205.1.4 Pressure-reducing
valves. Shutoff valves shall be installed
on both sides of a pressure-reducing valve.

1205.1.5 Equipment and
appliances. Shutoff valves shall be
installed on connections to mechanical equipment and appliances. This
requirement does not apply to components of a hydronic system such as pumps,
air separators, metering devices and similar equipment.

1205.2 Reduced pressure.
A pressure relief valve shall be installed
on the low-pressure side of a hydronic piping system that has been reduced in
pressure. The relief valve shall be set at the maximum pressure of the system
design. The valve shall be installed in accordance with Section 1006.

SECTION 1206

PIPING INSTALLATION

1206.1 General. Piping, valves, fittings and connections shall be installed
in accordance with the conditions of approval.

1206.2 System drain down.
Hydronic piping systems shall be designed
and installed to permit the system to be drained. Where the system drains to
the plumbing drainage system, the installation shall conform to the
requirements of the plumbing code.

Exception: The buried portions of systems embedded underground or under
floors.

1206.3 Protection of potable
water. The potable water system shall be
protected from backflow in accordance with the plumbing
code.

1206.4 Pipe penetrations.
Openings for pipe penetrations in walls,
floors or ceilings shall be larger than the penetrating pipe. Openings through
concrete or masonry building elements shall be sleeved. The annular space
surrounding pipe penetrations shall be protected in accordance with the
building code.

1206.5 Clearance to combustibles.
A pipe in a hydronic piping system in
which the exterior temperature exceeds 250°F (121°C) shall have a
minimum clearance of 1 inch (25 mm) to combustible materials.

1206.6 Contact with building
material. A hydronic piping system shall
not be in direct contact with building materials that cause the piping material
to degrade or corrode, or that interfere with the operation of the
system.

1206.7 Water hammer.
The flow velocity of the hydronic piping
system shall be controlled to reduce the possibility of water hammer. Where a
quick-closing valve creates water hammer, an approved water-hammer arrestor
shall be installed. The arrestor shall be located within a range as specified
by the manufacturer of the quick-closing valve.

1206.8 Steam piping pitch.
Steam piping shall be installed to drain
to the boiler or the steam trap. Steam systems shall not have drip pockets that
reduce the capacity of the steam piping.

1206.9 Strains and stresses.
Piping shall be installed so as to prevent
detrimental strains and stresses in the pipe. Provisions shall be made to
protect piping from damage resulting from expansion, contraction and structural
settlement. Piping shall be installed so as to avoid structural stresses or
strains within building components.

1206.9.1 Flood hazard.
Piping located in a flood hazard area
shall be capable of resisting hydrostatic and hydrodynamic loads and stresses,
including the effects of buoyancy, during the occurrence of flooding to the
design flood elevation.

1206.11 Condensation.
Provisions shall be made to prevent the
formation of condensation on the exterior of piping.

SECTION 1207

TRANSFER FLUID

1207.1 Flash point.
The flash point of transfer fluid in a
hydronic piping system shall be a minimum of 50°F (28°C) above the
maximum system operating temperature.

1207.2 Makeup water.
The transfer fluid shall be compatible
with the makeup water supplied to the system.

SECTION 1208

TESTS

1208.1 General. Hydronic piping systems other than ground-source heat pump
loop systems shall be tested hydrostatically at one and one half times the
maximum system design pressure, but not less than 100 psi (689 kPa). The
duration of each test shall be not less than 15 minutes. Ground-source heat
pump loop systems shall be tested in accordance with Section 1208.1.1.

1208.1.1 Ground source heat pump
loop systems. Before connection (header)
trenches are backfilled, the assembled loop system shall be pressure tested
with water at 100 psi (689 kPa) for 30 minutes with no observed leaks. Flow and
pressure loss testing shall be performed and the actual flow rates and pressure
drops shall be compared to the calculated design values. If actual flow rate or
pressure drop values differ from calculated design values by more than 10
percent, the problem shall be identified and corrected.

1209.2 Pressurizing during
installation. Piping to be embedded in
concrete shall be pressure tested prior to pouring concrete. During pouring,
the pipe shall be maintained at the proposed operating pressure.

1209.3 Embedded joints.
Joints of pipe or tubing that are embedded
in a portion of the building, such as concrete or plaster, shall be in
accordance with the requirements of Sections 1209.3.1 through 1209.3.3.

1209.3.2 Copper tubing joints.
Copper tubing shall be joined by brazing
with filler metals having a melting point of not less than 1,000°F
(538°C).

1209.3.3 Polybutylene joints.
Polybutylene pipe and tubing shall be
installed in continuous lengths or shall be joined by heat fusion in accordance
with Section 1203.10.1.

1209.4 Not embedded related
piping. Joints of other piping in cavities
or running exposed shall be joined by approved methods in accordance with
manufacturer's installation instructions and related sections of this
code.

1209.5.2 Suspended floor
installation. In suspended floor
applications, insulation shall be installed in the joist bay cavity serving the
heating space above and shall consist of materials having a minimum R-value of
11.

1209.5.3 Thermal break required.
A thermal break shall be provided
consisting of asphalt expansion joint materials or similar insulating materials
at a point where a heated slab meets a foundation wall or other conductive
slab.